Bypass of a spinal cord lesion may be an important procedure for the treatment of neurogenic bladder dysfunction. In this proposal we outline an experimental plan designed to investigate whether a lumbosacral nerve root connection via a nerve graft can lead to functional reinnervation of detrusor muscle. Twenty young adult female cats will undergo a laminectomy and a unilateral extradural L7 to S2 anastomosis of the mixed roots via a nerve graft. Ten animals will have nerve roots connected by a conventional microsurgical approach and the other ten cats will have the L7 to S2 root connection performed using an approach designed to enhance the regenerative capability of the axon. These roots will be exposed to focal transient freezing while bathed in a solution of composition believed similar to that of the intracellular medium. After transection and rewarming, these L7 and S2 roots will be connected using a biogradable support to distribute evenly forces at the anastomotic site. In all cats, remaining ipsilateral sacral roots will be sectioned while contralateral sacral roots will be preserved to allow urination. After a period of six months, all animals will undergo reoperation and evaluation of the anastomosed roots for regeneration. The nerve regeneration achieved will be compared between the two techniques and assessed by electrophysiological, cystomeric and histological parameters. The contralateral sacral roots will be transected immediately prior to cystometry in order to determine whether a micturition reflex through the regenerated L7 root is present. This information could lead to the development of a clinical method for the reinnervation of the urinary bladder.